1 /*
2 * Copyright (C) 2012-2014 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include <stdlib.h>
18
19 #include <private/android_filesystem_config.h>
20
21 #include "FlushCommand.h"
22 #include "LogBuffer.h"
23 #include "LogBufferElement.h"
24 #include "LogCommand.h"
25 #include "LogReader.h"
26 #include "LogTimes.h"
27 #include "LogUtils.h"
28
29 // runSocketCommand is called once for every open client on the
30 // log reader socket. Here we manage and associated the reader
31 // client tracking and log region locks LastLogTimes list of
32 // LogTimeEntrys, and spawn a transitory per-client thread to
33 // work at filing data to the socket.
34 //
35 // global LogTimeEntry::wrlock() is used to protect access,
36 // reference counts are used to ensure that individual
37 // LogTimeEntry lifetime is managed when not protected.
runSocketCommand(SocketClient * client)38 void FlushCommand::runSocketCommand(SocketClient* client) {
39 LogTimeEntry* entry = NULL;
40 LastLogTimes& times = mReader.logbuf().mTimes;
41
42 LogTimeEntry::wrlock();
43 LastLogTimes::iterator it = times.begin();
44 while (it != times.end()) {
45 entry = (*it);
46 if (entry->mClient == client) {
47 if (!entry->isWatchingMultiple(mLogMask)) {
48 LogTimeEntry::unlock();
49 return;
50 }
51 if (entry->mTimeout.tv_sec || entry->mTimeout.tv_nsec) {
52 if (mReader.logbuf().isMonotonic()) {
53 LogTimeEntry::unlock();
54 return;
55 }
56 // If the user changes the time in a gross manner that
57 // invalidates the timeout, fall through and trigger.
58 log_time now(CLOCK_REALTIME);
59 if (((entry->mEnd + entry->mTimeout) > now) &&
60 (now > entry->mEnd)) {
61 LogTimeEntry::unlock();
62 return;
63 }
64 }
65 entry->triggerReader_Locked();
66 if (entry->runningReader_Locked()) {
67 LogTimeEntry::unlock();
68 return;
69 }
70 entry->incRef_Locked();
71 break;
72 }
73 it++;
74 }
75
76 if (it == times.end()) {
77 // Create LogTimeEntry in notifyNewLog() ?
78 if (mTail == (unsigned long)-1) {
79 LogTimeEntry::unlock();
80 return;
81 }
82 entry = new LogTimeEntry(mReader, client, mNonBlock, mTail, mLogMask,
83 mPid, mStart, mTimeout);
84 times.push_front(entry);
85 }
86
87 client->incRef();
88
89 // release client and entry reference counts once done
90 entry->startReader_Locked();
91 LogTimeEntry::unlock();
92 }
93
hasReadLogs(SocketClient * client)94 bool FlushCommand::hasReadLogs(SocketClient* client) {
95 return clientHasLogCredentials(client);
96 }
97
clientHasSecurityCredentials(SocketClient * client)98 static bool clientHasSecurityCredentials(SocketClient* client) {
99 return (client->getUid() == AID_SYSTEM) || (client->getGid() == AID_SYSTEM);
100 }
101
hasSecurityLogs(SocketClient * client)102 bool FlushCommand::hasSecurityLogs(SocketClient* client) {
103 return clientHasSecurityCredentials(client);
104 }
105